On the robustness of quantum bucket brigade RAM - Priyaa Varshinee Srinivasan

Quantum RAM serves as an oracle which is a necessary component in the implementation of many quantum search algorithms such as Grover's search, element distinctness problem and collision finding algorithm. In 2008, Giovanni et.al. published bucket brigade architecture for quantum RAM and discussed its advantages over the fan-out architecture used by classical RAMs. They showed that a quantum RAM based on bucket brigade design consumes far lesser number of resources in terms of number of two qubit logical operations. In our study, we analysed the bucket brigade design based on certain simple error models for Grover's search. In this talk, I would present our analysis and the results. A previous study shows that Grover's search algorithm with faulty oracle loses its quadratic speed up, which means that error correction is needed for any qRAM circuit. Our analysis shows that the resource advantage bucket brigade qRAm is lost on applying error correction to the circuit. My talk is based on a recent paper uploaded to arXiv, which was also presented at TQC 2015. Arunachalam, Srinivasan, Vlad Gheorghiu, Tomas Jochym-O’Connor, Michele Mosca, and Priyaa Varshinee Srinivasan. 2015. “On the Robustness of Bucket Brigade Quantum RAM.” arXiv:1502.03450, Feb.